Scientists determined the concentration of cholesterol in lysosome membranes from a mammalian cell. It was lower in the lysosome membranes than in other membranes within mammalian cells.
State how a reduced cholesterol concentration would alter lysosome membrane properties compared with other membranes in mammalian cells.
Suggest why a lower cholesterol concentration in lysosome membranes would assist lysosomes in performing their function.
$\alpha$-galactosidase is found in lysosomes. Students examined how substrate concentration affected the rate of the reaction catalysed by $\alpha$-galactosidase at $\text{pH }4.5$ and at $\text{pH }5.9$. The data are displayed in Fig. 4.1.
Determine the Michaelis-Menten constant, $K_m$, for $\alpha$-galactosidase at pH 4.5 from the data in Fig. 4.1. Give the unit for the $K_m$ value in your response.
Using Fig. 4.1, describe how the results differ between pH 4.5 and pH 5.9 and suggest reasons for those differences.